One of Earth's most toxic animals, poison dart frogs are famed for their colourful, vibrant appearance.
Amphibian vs reptile: what's the difference?
Despite their small size, measuring just one inch in length, these tiny amphibians possess enough potent toxins to deter or even kill predators many times their size.
Their bright hues serve as a warning signal to potential threats, showcasing nature's powerful yet deadly beauty.
What are poison dart frogs?
Poison dart frogs belong to the family Dendrobatidae. There are approximately 200 species and they are found in the tropical rainforests of Central and South America.
Their poison is used by tribes to tip their blowgun darts when hunting, giving the amphibians their common name.
Many Dendrobatidae species are poisonous, with varying degrees of toxic skin, but some are more deadly than others. One in particular is famously considered to be one of the world's most poisonous animals.
What’s the most toxic poison dart frog?
Poison dart frogs secrete toxins through their skin, which can cause symptoms ranging from mild numbness to paralysis, and even death.
The Endangered golden poison frog (Phyllobates terribilis) is endemic to the rainforests of Colombia, and though it is only about 5cm long, it packs a considerable punch. Its toxins affect the nerves and heart and it has enough poison to kill 20,000 mice or about 10 grown men.
Which other species are poisonous?
Dendrobatidae includes 16 genera that are mostly brightly coloured and have different levels of toxicity (Dendrobates, Minyobates and Phyllobates, for example). However, some species in the family are cryptically coloured (blend in with their surroundings) and non-toxic (Colostethus, for example).
According to xPharm: The Comprehensive Pharmacology Reference, “Only poisonous frogs from the genus Phyllobates, especially the species Phyllobates terribilis [golden poison frog], Phyllobates bicolor [black-legged poison dart frog] and Phyllobates aurotaenia [Kokoe poison frog], secrete batrachotoxin, the toxin used to poison the tips of darts for hunting by South American tribes.”
What do poison dart frogs eat?
Poison dart frogs use their sticky, retractable tongues to catch and consume invertebrates, including ants, termites and beetles.
Why are poison dart frogs poisonous?
A common theory is that the toxic compounds in the skin come from the insects that they eat, which may in turn acquire the poison from their plant diets.
The toxins accumulate in the frogs’ skin as a defence mechanism against predators. As a result, poison dart frogs don’t develop poison when they are raised in captivity and isolated from the insects that are found in their native habitat.
A PNAS study (2005) on poison dart frogs and their arthropod prey states that myrmicine and formicine ants, and the millipede Rhinotus purpureus, are dietary sources for toxins in frogs belonging to the Dendrobatidae family.
Are poison dart frogs used in medicine?
Yes. Researchers developed a new painkiller called ABT-594 after isolating a poison from the skin of a phantasmal poison frog (Epibpedobates tricolor), naming it epibatidine in honour of the amphibian.
They found that the compound could block pain 200 times more effectively than morphine, and created a synthetic version. Due to severe side effects, though, ABT-594 (the first analogue of epibatidine), is not included in current pain therapies for humans.
Another new derivative of epibatidine, ABT-418, is used in the treatment of less severe ADHD in adult patients, reports Biomolecules (2019).
Why are poison dart frogs so colourful?
Known as aposematic coloration, the bright colours and markings – yellows, oranges, reds, greens and blues – of many poison dart frogs warn potential predators not to eat or attack them. As a general rule, poison dart frogs that display vibrant hues are more poisonous than dull-coloured species.
Where do poison dart frogs live?
Poison dart frogs inhabit rainforests because they need high humidity and reasonably stable temperatures. They favour leaf litter, rotting logs and vegetation near streams or other bodies of water. These amphibians can swim, but it’s more challenging for them as they’re not equipped with webbed feet. Instead, they have adhesive pads on the tips of their toes to help them while climbing and hanging.
How do poison dart frogs mate and reproduce?
Poison dart frogs breed all year, but rainfall controls the timing of activity. Many species engage in complex and elaborate courtship behaviour, including calling, postural displays and tactile interactions.
Frog breeding behaviour: How frogs mate and produce spawn
The male leads the female to a suitable site to lay her eggs, which he then fertilises. However, in some species, the male fertilises the eggs before they are laid. The brood is guarded and eggs are kept moist until they hatch.
Evolutionary Ecology states, “Depending on the species, tadpoles are carried by males or females, singly or in groups, and released in terrestrial or arboreal pools ranging from large streams to small water-filled plants.” These ‘piggyback rides’ transport the tadpoles to where they will complete their development.
How long do poison dart frogs live?
In the wild poison dart frogs can live up to 13 years
What threats do they face?
Poison dart frogs have only one known natural predator, the fire-bellied snake, which is resistant to the frogs’ toxins.
But habitat loss caused by deforestation, pollution (from agriculture and mining practices) and the deadly chytrid fungus Batrachochytrium dendrobatidis are all threats, placing many species on the IUCN Red List.
These bold-coloured amphibians are also prized by the illegal pet trade.
Discover more fascinating frog facts